Lock-joint chair



March 19, 1963 H. w. ANDERSON 3,082,037

LOCK-JOINT CHAIR Filed Oct- 19, 19 60 2 Sheets-Sheet 1 FIG. 3.

INVENT OR Howard W. A ndersoh March 19, 1963 H. w. ANDERSON 3,082,037

LOCK-JOINT CHAIR Filed Oct. 19, 1960 2 Sheets-Sheet 2 INVENT OR HbwordW. Anderson United States Patent 3,082,037 LOCK-JOINT CHAIR Howard W.Anderson, 1110 S. 38th, Tacoma 8, Wash- Filed Oct. 19, 1960, Ser. No.63,637 1 Claim. (Cl. 297-440) This invention relates generally tofurniture, and particularly to the construction of a novel selfinterlocking chair.

The design of modern furniture has demanded some measure of ingenuityfrom the manufacturer who must produce a stable and economical structureto meet the designers requirements. One of the high costs in themanufacture of furniture involves the actual assembly of the differentparts. Another important factor is shipping cost which is a function ofthe volume of the crated article. This invention is concerned withminimizing these factors without sacrifice to design or utility.

It is therefore a primary object of this invention to provide a chairconstructed of parts which may be assembled without adhesives and whichmay be dismantled at will for storage purposes.

It is a further object of this invention to provide a chair constructedof parts which are self interlocking to provide a chair of modern designand comfortable in use.

It is a still further object of this invention to provide a chairconstructed from a minimum number of parts which are self interlockingto provide a chair which is highly economical in manufacture and indistribution to the consumer market.

The invention consists of a vertically disposed central support memberhaving a downwardly extending leg projecting from the forward end and anupwardly extending back support spaced rearwardly of the leg. A cradlemember is provided with two spaced legs and upwardly disposed cradlearms spaced to receive an arcuately sprung seat. The cradle interlockswith the central support to form a tripod support with the three legs,and a back rest embraces the back support and is arcuately sprung toengage and interlock between the cradle arms. A transverse seat braceinterlocks with the support member above the leg to provide furthersupport for the seat.

A full understanding of the construction of this invention, togetherwith further novel features and advantages, will be had from thefollowing detailed description of a preferred embodiment thereof, takenin conjunction with the attached drawings wherein:

FIG. 1 is a front elevation of the chair fully assembled.

FIG. 2 is a side elevation of the chair which comprises my invention.

FIG. 3 is a fragmentary view shown partly in cross section showing themethod of securing the back support to the leg framework.

FIG. 4 is a fragmentary cross sectional view taken along the line 4-4 ofFIG. 1.

FIG. 5 is an exploded view of the three interlocking members whichcombine to form the frame.

FIG. 6 is a plan view of the seat in a fiat unassembled condition.

FIG. 7 is a plan view of the chair back, also in the flat unassembledstate.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawing.

Referring now to the drawings in detail, and particularly to FIG. 2 andFIG. 5, the numeral 10 represents a Z-shaped central support memberwhich provides support for a seat 11 and a back rest 12. The member 10has a central section 13 having an upper edge 35 adapted to locatesubstantially parallel to the ground. The for- "ice ward end of member10 terminates with a downwardly extending front leg 14. The rear end ofmember 10 projects upwardly to form a support 15 for the back rest 12.The back support 15 has a forwardly facing support surface 16 disposedat a slightly obtuse vangle relative to the upper edge 35 of the centralsection 13. The leg 14, central section 13 and back support 15 are cutfrom one piece of material. A vertical slot 17 is provided transverselyacross the forward end of the central section 13 and a second slot 18 isformed at the junction between the back-support 15 and the rear end ofthe central section 13. The slot 18 is cut from the underside of thementioned location and is formed at an acute angle relative to the frontleg 14. A spur or spigot 19 projects from the upper end of supportsurface 16 to complete the central frame support member 10.

A cradle member 20 is provided with two spaced downwardly projectinglegs 21. Curving outwardly and upwardly above each leg 21 are cradlearms 22. The upwardly directing edge of the arms 22 connect to form anarcuate face 23 which terminates at each end with inwardly projectingspigots 24. The cradle member is likewise cut from a single sheet ofmaterial and is further provided with a transverse slot 25 cut into thecentre of the arcuate face 23.

A seat brace 26 consists of two arms 27 which provide an arcuate seatsupport face 28. Centrally of the two arms is a downwardly extendingprotrusion 29 which is bifurcated by a vertical transverse slot 30.

The seat 11 shown in FIG. 6, is shaped with a slightly convex rear edge32 having a slot 33 cut into the centre. The forwardly disposed edge 34is substantially oval in shape and completes the peripheral edge of theseat. A small hole 35 is formed at each end of the seat at the points ofintersection of the two edges 32 and 34.

The back rest 12 shown in FIG. 7, has an upper edge 37 of arcuate formand a lower edge 38 of substantially elliptical shape. The two edges 37and 38 meet at points 39 and 40. A small hole 41 is located adjacent thecentre of the upper edge 37 and two further holes 42 are formed adjacentthe meeting points 39 and 40.

The assembly of the lock joint chair may be carried out in the followingsequence. The cradle member 20 and the central support member 10 areconnected by interlocking the slots 25 and 18 respectively in anoverlapping manner such that the arcuate face 23 of the cradle alignswith the upper edge 25 of the central support member. Leg 14 and legs 21now support the two elements in a tripod configuration. The seat brace26 is now interlocked with the central support member 10 by means of thetwo slots 17 and 30. Engagement is made such that the support face 28transversely aligns with the upper edge 35 of the central sup ortmember. The support framework is now complete. The seat 11 is then bowedsuch that the small holes 35 engage over the spigots 24 which projectfrom each end of the arcuate face 23. At the same time the slot 33engages about the base of the back support 15. The back rest 12 is thenbowed in a similar manner to that of the seat such that the spigot 19,projecting from the back support 15, engages in the hole 41 and thespigots 24 engage in the holes 42. The sprung condition of the seat andthe back rest provide a rigid relationship with the support framework tocomplete a sturdy utilitarian chair of exceedingly pleasing design.

Having described the invention with considerable part cularity, itshould be understood that various modificatrons may be made to thedetail thereof, without departmg from the scope or spirit of theinvention as defined in the appended claim.

I claim:

A self interlocking chair comprising, a fiat vertically disposedrearwardly extending central support member, a leg extending downwardlyfrom the forward end of the support member, an upwardly extending backsupport rearwardly spaced from said leg by a horizontally extending seatsupport section, a flat cradle member having two spaced legs and twoupwardly extending arcuately formed cradle arms, inwardly projectingspigots projecting inwardly from the ends of the cradle arms, a slotformed intermediate the cradle arms inwardly of their upper edge forinterlocking engagement with a second slot formed in the underside ofsaid seat support section, a fiat seat brace interlocking transverselywith the forward end of the upper edge of the seat support section, aseat arcuately sprung to engage between the ends of the cradle arms andembrace the seat support section and the seat brace, the ends of theseat having means interlocking with said spigots, and a back restarcuately sprung to engage between said cradle arms and embrace the backsupport, said back rest having similar means for interlocking with saidspigots, said arcuately sprung seat and said arcuately sprung restmaintaining the interlocking engagement of the fiat cradle member withthe central support member and said seat brace with the central supportmember.

References Cited in the file of this patent UNITED STATES PATENTS2,541,835 Saarinen Feb. 13, 1951 2,546,812 Anderson Mar. 27, 19512,628,668 Basile Feb. 17, 1953 2,890,744 Ng June 16, 1959 OTHERREFERENCES Horne Craftsman, Jan-Feb. 1950, page 17.

